Control system



Sept. 11, 1945. H. B. HOLTHOU SE CONTROL SYSTEM Filed Jan. 19, 194% 2 Sheets-Sheet 1 jZzry ,5? 170/ #0141522 Sept. 11, 1945. H. B. HOLTHOUSE QONTROL SYSTEM Filed Jan. 19, 1942 2 sheets-sheet 2 Patented Sept. 11, 1945 UNITED" STATES PATENT OFFICE.

I CONTROL SYSTEM Harry B. Holthous'e, Chicago, 111., assignor to Galvin Manufacturing Corporation, Chicago,

111., a corporation of Illinois Application January 19, 1942, Serial No. 427,354

19 Claims.

ing unit to have air supplied to the unit prior to the admission of any fuel thereto so as to prevent I the occurrence of any explosions on initiation of ignition.

A further object of this. invention is to provide a control system for a. heater of internal combustion type having air and fuel supplied thereto for burning by means operated by a common motor, in which the motor operating circuit is made operative to start the motor prior to the energization of the circuit for the heater ignition means, and time delay means are operatively related with the fuel supply means for the heater so that fuel is admitted to the heater only after the heater air supply means and ignition circuit are in operation.

Another object of this inventionis to provide a control system for. a heating unit comprising a burner direct connected for operation with an internal combustion engine, which provides for a positive operation of the unit, is comprised of but a fewparts requiring a minimum of adjustment and servicing attention, and which 'is adapted to always start the unit according to a predetermined pattern of operations to provide maximum operating safety and eillciency.

bustion burner operatively connected with an internal combustion engine showing one form of the control system applied thereto; a

Fig. 2 is a fragmentary sectional view as seen along the line-2-2 in Fig. 1 showing an air and fuel mixing device for the burner;

Fig. 3 illustrates diagrammatically a battery circuit for the engine and the burner in the heating unit i Fi 1; a

Fig. 4 is a diagrammatic perspective view of a heating unit similar in all respects to the heatin unit of Fig. 1 but embodying,a modified form of control system;

Fig. 5 is a. transverse sectional view taken along the line 5-5 in Fig. 4 showing the construction of a control mechanism utilized in the control system of Fig.

Fig. 6 is a plan sectional view as seen along the line 6-6- in Fig. 5; and

Fig. '1 is a detail view of a sail switch used in the control system illustrated in Fig. 4.

In practicing this invention there is provided a heating unit including a burner of internal combustion type having a combustion chamber operatively associated with an air and fuel mixin device. The burner is operated entirely in con- A particular feature of this invention is found I in the provision of a control system for a heating unit including a burner having fuel vaporizing means heated by exhaust gases from an internal combustion engine operatively associated with the burner, which provides for the operation of the air supply means and the ignition circuit for the burner prior to the admission of fuel thereto,,and

includes means for delaying such admission of fuel until afterthe vaporizing means has been heated to at least a fuel vaporizing temperature by the engine exhaust gases.

Further objects. features, and advantages ofthis invention will become apparent from the following description when taken in connection with the accompanying drawings in which:

Fig. 1 is a front perspective view partly in section of a heating unit including an internal comjunction with an internal combustion engine adapted to operate a fuel pump and blower for supplying fuel and air, respectively, to the air and fuel mixing device and hence to the burner. In the operation of the heater, the mixing device is heated to at least a fuel vaporizing temperature by the exhaust gases from the engine, so that the fuel supplied to the mixing device is practically completely v porized for mixing togetherwith the air in the device prior to the passage of the mixture into the burner combustion chamber. The invention, contemplates the provision of a control system for the heating unit which operates in part to provide for the initial operation of the engine for a period oftime suflicient to allow the exhaust gases therefrom to heat the mixing device to at least a fuel vaporizing temperature. By virtue of the air blower being in a driven connection with the engine, combustion air is supplied to the burner immediately on startns of the engine,- with means being provided to set the burner ignition system in operation before the mixing device is heated to its fuel vaporizing temperature. A valve in the fuel line leading from the engine-operated fuel pump to the mixing device, is actuated by means responsive in operation to the temperature of the mixingdevice. When. the mixing device reaches a substantially fuel vaporizing temperature the-valve actuating means operates the valve to admit fuel to the mixing device. Thus the control system functions to have the burner air supply and ignition means in operation prior to the supply of any fuel to the burner combustion chamber so as to completely eliminate any occurrence of explosions which might result from fuel accumulations in the combustion chamber. Since fuel is supplied to the burner only after the mixing device therefor is completely operative to vaporize the fuel for mixing with the air, combustion in the burner is complete and efficient immediately at the inception of burner operation.

Referring to the drawings there is shown in Fig. 1 an internal combustion engine In of air cooled type including a base H, a fuel tank l2, and a cylinder l3. The engine crank shaft It extends outwardly from each side of the engine W, with one end "5 thereof carrying a blower l1 for cooling the cylinder'|3, and a magneto l8 operatively associated with a spark plug l9 in the engine cylinder l3, and a plug or igniter 2| provided in a heater or burner 22 of internal combustion type. The opposite end 23 of the engine crank shaft H has mounted thereon a cam 24 for operating a pump 26 adapted to supply fuel for burning to the heater 22. Also mounted at The combustion chamber 29 has a tubular outer wall 32 having one end closed by a cover plate 33 and an opposite end 94 by the base portion 36 of a substantially cup-shaped member 31 which defines the air chamber 3|. The open end of the member 31 is closed by a cover or end plate 38 for the housing member 28. Thus as is evident from Fig. 1 the air chamber 3| and combustion chamber 29 are in alignment axially of the housing member 28 and separated from each other by the base portion 36 of the cup-shaped member 31. These two chambers are spaced from the heater housin 28 by fins 39 angularly spaced about the combustion chamber wall .32 and extending axially thereof to provide an annular passage about the chambers 3| and 29. The air to be heated is circulated through the passage 4| by the fan or blower 21, the casing or scroll of which includes the cover plate 38 and a radially extending L-shaped portion 42 of' the housing member 28. The portion 42 is formed with an air inlet 43, the air after being circulated about the combustion chamber 29 through the passage 4| being discharged from the heater 22 through the outlet 44 thereof.

The combustion chamber 29 is divided into four axially extending passages 46a--48d by a partition member 41 of substantially X-shape and of a construction providing for the connecting of such four passages to form a-single continuous passage in the chamber 29. By virtue of. this construction of the continuous passage the inlet 48 and outlet 49 of the passage and hence of the combustion chamber 29 areboth located in the base portion 36 of the cup-shaped member 31.

Located within the air chamber 3| and at the inlet 49 to the combustion passages 46a46d is a fuel conditioning unit (Fig. 2) designated generally as 5| and including a substantially tubular shaped housing 52 closed at one end 53 and having the opposite or outlet end 54 thereof in fluid communication with the combustion chamber passage 46a. As is evident from Fig. 1 the greater part of the conditioning unit 5| extends within the air chamber 3|. The housing member 52 is constructed of a high heat conducting material and includes an air and fuel mixing chamber 55 at the closed end 53 thereof and an equalizing chamber 51 adjacent thereto, the mixing chamber 56 and equalizing chamber 51 being separated by a heat conducting partition plate 58 having perforations 59 therein fluid connecting such two chambers (Fig. 2). The equalizing chamber 51 in turn is separated from the combustion passage 46a by a heat insulating plate 6| having perforations 62 arranged peripherally therein. Extending axially through the housing member 52 and supported in the housing end 53 and partition plates 59 and 62, is a heating element or conduit portion 63 having an inlet end 64 at the housing closed-end 53 and an outlet portion 68 extending with the combustion passage 46a.

Arranged in a spaced concentric relation about that portion of the housing member 52 which extends into the air chamber 3| is a conduit portion 61 in sealed engagement at one end 68 with the base portion 36 of the member 31 and connected at its opposite end 69 with an exhaust conduit 1| from the engine Hi. The annular space formed within the conduit 61 and about the housing member 52 is divided into connected passages 12 and 13 by a partition or baflie plate 14 adapted to direct the exhaust gases entering the conduit 61 from the exhaust pipe 1| to travel in the passage 12 to the conduit end 68, and then in an opposite direction in the passage 13 into the inlet 64 of the heating element 63, from where it is discharged through the heating element outlet 66 into the combustion passage 46a. Since the housing member 52, partition plate 58 and heating element 63 are all constructed of high heat conducting material, the heat from the engine exhaust gases passing about the housing 52 and in the passages 12 and 13 is readily transferred to the heat conditioning unit 5| for a purpose now to be explained.-

The fuel conditioning unit 5| has an inlet 16 at the closed end 53 thereof in which is positioned an air and fuel nozzle 11. As best shown in Fig. 2 the nozzle 11 has one end thereof extending through the conduit 61 into the air chamber 3|. This extending end of the fuel nozzle 11 is connected through a pipe 18 with the fuel pump 26, which is in fluid connection with the fuel tank |2 through pipe 19. The fuel from the nozzle 11 is introduced into the mixing chamber 58 of the fuel conditioning unit together with combustion air from the air chamber 3|, this combustion air being admitted into the fuel nozzle through ports 8| and through tubes 82 arranged about the inlet 16 and connecting the mixing chamber 56 with the air chamber 3|. The fuel thus admitted into the mixing chamber 56 is heated and vaporized for mixing together with -the air therein, the vaporous mixture passing through the apertures 59 in the artition plate 58 and into the equalizing chamber 51 from where it is discharged through the apertured insulating plate 6| into the combustion passage 46a. This vaporous mixture is mixed with the exhaust gases from the heating element outlet 66 for burning therewith in the combustion chamber 29. Combustion is initiated by the spark means 2| positioned in the combustion chamber passage 46a and operatively connected in a manner to be later fully explained primary P by virtue of with the engine magneto I0. The gases from combustion are exhausted from the combustion passage outlet 49 into a tail piece assembly 93 for discharge from the heater.

As previously mentioned the air for,combustion in the chamber 9| is supplied by the blower or fan 21. As shown in Fig. 1 a portion of the cup-shaped member 31 has an opening 50 formed therein with radially extending portions 55 of a contour corresponding to the fan 21. Thus a portion of the air delivered by the fan is diverted for passage into the chamber the remaining portion going into the air circulating passage ll of the heater. a

From the above description it is seen that when the heater 22 is in operation the conditioning unit BI'is heated to a substantially fuel. vaporizing temperature by the exhaust gases from the engine I0 to provide for a thorough mixing of the air and fuel in the unit and consequently for a complete and emcient burning of all of the fuel supplied to the burner. This manner of operating the heater 22 at all times of heater operation is accomplished in the present invention by the novel control system now to be described.

with reference to Fig. 1 the control system shown therein includes an ignition circuit for the engine I0 comprising the spark plug I9 connected to a secondary winding S of the magneto I 0 by a conductor 00. The primary winding P of the magneto is selectively connected with an engine ground, indicated at 99, through conductor 92, normally closed thermostatic switch 99, conductor 90 and a normally closed manually operated control switch 90 having one contact 95 thereof grounded to the engine base I I.- The spark means 2I for the heater 22 is grounded to the heater as indicated at 91 and is connected with the secondary S of the magneto I9 through conductor 99 normally open thermostatic switch means 99, and conductor IOI. means 93 in the e'ngineignition circuit is thermally connected with the combustion chamber 29 so as to be responsive to the temperature thereof, .while the thermostatic switch means 99 in the heater ignition circuit is mounted on the engine exhaust conduit 1I so as to be actuated in response to the temperature thereof.

The manually operated control switch 90 includes an actuating arm I02 which is also common to a valve unit I02 connected in the fuel line 19. A cam I00 carried by the valve unit I03 is in a following operating relation with the contact I00 of switch 90 so that pivotal movement of the actuating arm I02 opens and closes the'cone tacts I09 and 95 concurrently with an operation of the valve I 00 to control the supply of fuel to the pump 20. When the heater 22 is not in o eration the actuating arm I02 is in its position The thermostatic switch opening of the valve unit I02 to admit fuel from the tank I2 to the pump 20. The opening of "the. control switch removes the ground 90 from the primary P of the magneto I0 to permit a spark beingproduced at the plug. I9. his to be understood of course that with the engine ignition circuit thus made operative that the closed thermostatic switch 99 is ineffective grounding the its series connection with the switch unit 90. with the engine ignition circuit thus madeoperative, the engine I0 may be closed'valve unit I01 inserted in the fuel line 10 between the fuel injection nozzle 11 and the pump 26. It is seen, therefore, that only .air is delivered to the burner when the engine I0 is first started.

It is apparent, of course, that with the engine I0 in operation the exhaust gases therefrom are discharged through the conduits H and 51 and through the heating element 63 into. the combustion passage 00a. With a continued" operation of the engine I0 the heat from these exhaust gases in the conduit 1I act on the normally open A thermostatic switch means 99 to provide fora closing of the same, this closing of the thermostatic switch means 99 connectin the plug 2I with the secondary S of the magneto I9. Thus on closing of the switch means 99 the burner ignition circuit is Set into operation to fire any combustible mixture which might be present in the combustion chamber passage 46a. This sequential operation of the fan 21 and spark plug 2|, serves to safely dispose of any fuel accumulations in the device 5| and combustion chamber 29 prior to the admission of any. fuel to the fuel mixing device SI.

As the engine I0 continues in operation the temperature of the fuel conditioning unit 5| continues to increase. Located within the equalizing chamber 51 and secured to the heating element 89 of the conditioning unit 5I is a bulb I08,'which is formed as a part of a Sylphon type unit designated generally as I05, for operating the valve unit I01. The bellows for the unit I05, indicated at I09, is in sealed connection with the bulb I08 through a tube III. When the temperature of the conditioning unit 5| is increased to at least a fuel vaporizing temperature the bellows I09 is acted upon -by the sealed fluid in the unit I05, in a well known manner, to open the valve I01, whereby fuel is admitted into the mixing chamber 50 of the conditioning 'or fuel vaporizing unit 5I. This pro-heating of the conditioning unit 5i to at least a fuel vaporizing temperature, prior to the admission of any fuel thereto; provides for a substantially complete vaporizing of the fuel with the air, so that the fuel is prepared for eiiicient burning immediately at the inception of heater operation. It is seen, therefore, that instarting the heater the blower 21 is initially operated with the thermostatic means 99 being adjusted so as to next operate the burner ignition circuit at some predetermined tim prior to the operation of the valve unit I01 by the heat responsive means or Sylphon unit I05.

In stopping operation of the heater the actuating arm I02 is returned to its starting position (shown in Fig. 1), the closing of the valve I03 cutting off anyfurther supply of fuel to the pump 20 and the closing of the contacts I05 and inthe control switch 90 grounding the conductor 92 "at 09; However, this grounding ofthe conductor 92 is ineffective to stop the operation of the engine I0 because of the thermostatic switch 93 having been opened by the heating of the combustion chamber 29 during the operation of the heater 22. The engine II) and the heater 22 will thus both continue in operation after the closing of the switch 96 until the fuel remaining in the lines 18 and 19 between the nozzle 11 and valve unit I03 is pumped into the fuel conditioning unit 5 I. When this situation occurs the heater 22 will stop and the chamber 29 will start to cool, this cooling of the chamber 29 being accelerated by virtue of the 'blower 21 continuing in operation so that air continues to be circulated about the chamber 29 in the passage M. It is understood of course that air also continues to be supplied to the conditioning unit 5! from the chamber 3|. When the chamber 29 has cooled to a predetermined temperature value the thermostatic switch 93 closes and grounds the primary P of the magneto I8 thus rendering the engine ignition circuit inoperative and stopping the engine I0. On cooling of the exhaust conduit 1| and the conditioning, unit 5| the thermostatic switch means 99 and the valve unit I61 corresponding, respectively, to these parts are permitted to return to their starting positions, namely, the thermostatic switch means 99 is opened and the valve unit I 01 is closed.

It is seen, therefore, that the control system of Fig. 1 operates to provide for a complete scavenging of the combustion chamber 29 prior to the admission of any fuel thereto, with such fuel being admitted only when the conditioning unit BI is capable of vaporizing it for mixing together with the air for combustion. On the stopping of heater operation a time delay is provided for the engine III, :by the thermostatic switch 93, so'that th fan 21 continues in operation to substantially dissipate any and all fuel which might have accumulated in the combustion chamber 29 during the normal operation of the heater. Because of the sequential operation of the engine ignition circuit, the burner ignition circuit, and the burner air and fuel supply means both at the starting. and stopping of heater operation the control system afl'ords maximum safety of operation by completely eliminating any danger of explosions or back-firing in the heater 22. I

It is apparent, of course, that the control system above described in connection with Fig. 1 is readily adaptable for operation with a batteryoperated engine, battery operated ignition circuits for the heater 22 and engine I0 being diagrammatically illustrated, by way of example, in Fig. 3. With reference to Fig. 3 the thermostatic switch 93 and control switch 96 in the engine ignition circuit are connected in parallel across the battery II2, with each switchconnected in series with the spark plug I9. The distributor and coil for the engine ignition circuit are indicated at Ifla and "lb, respectively. When the engine I0 is first started by closing the switch 96 the switch unit 93 is open, and remains open until closed by the heat acting thereon from the combustion chamber 29. During normal operation, therefore, both switches 93 and 96 are closed. On opening of the control switch 96 to shut the engine down, the engine continues to operate because of the switch 93 being closed. Switch 93 remains closed until the combustion chamber 29 has cooled down to a predetermined temperature. When both switches 93 and 96 are in an openposition the engine ignition circuit is rendered inoperative and the engine is stopped, the delayed shutting off of the engine after the opening of the switch 96 providing for a delayed operation of the fan 21.

The ignition circuit for the heater 22 includes the thermostatic switch unit 99 and. the spark plug 2i which are connected in series across the battery 2, the coil for the circuit being shown at 2Ia. The thermostatic switch 99 in this battery circuit is normally open and is closed in response to the heat from the conduit H to complete the circuit for the plug 2|. Since all oi the other parts to be used with the battery ignitionsystem in Fig. 3 areidentical in all respects to the parts fully described above in connection with the magneto ignition system of Fig. 1, a further description of the battery operated circuit of Fig. 3 is believed to be unnecessary.

In Figs. 4-7, inclusive, there is shown a modified form of control system, with the heatin unit including the engine and the heater or burner 22 being illustrated somewhat diagrammatically in Fig. 4. It is to be understood, however, that the heating unit operated by the control system of Figs. 4-7, is identical in all respects to the heating unit of Fig. 1. Similar numerals of reference shall be used, therefore,

in Figs. 4-7, to designate heating unit parts therein similar to the corresponding parts in Fi 1.

- As shown in Fig. 4 the engine ignition circuit includes the plug I9 which is connected by conductor 88 to the secondaryS of magneto I6, the primary P, when the circuit is inoperative, being grounded through conductor H3 and switch H6. The switch H6 (Figs. 4 and 6) is formed as a part of a manual control mechanism II9 having a casing I I8 secured to the heater housing member 28. Switch Ill is positioned within the casing H8 and includes normally open contacts Ill and H1, contact Ill being connected with conductor H3 and the contact II1 being connected to the casing II6 for grounding as indicatedat I28.

The ignition circuit for the burner (Fig. 4) comprises the plug M which is connected with the secondary S of the magneto I6 through conductors I I9 and I2I the plug ground being shown at 91. This circuit, when inoperative, is grounded through a sail switch unit I22 connected by conductor I23 to the junction I24 of the conductors H9 and I2l. The sail switch unit I22 (Fig. '7) includes a pair of contacts I26 and I21, the contact I26 being connected to the heater cover plate 38 as a ground, indicated at I29, and the contact I21 being connected with the conductor I 23. The switch unit I22 is secured by suitable means to the cover plate 36 of the heater housing member 29, with a sail I25 having an axis portion I29 pivotally supported in the plate 38 and arranged topermit a pivotal movement of the sail I26 in response to the airflow created by the fan 21.- As clearly shown in Fig. 1 the plate 36 forms a part of the housing for the fan 21 so that the sail portion I26 is positioned adjacent the inner side of the plate 38 with the axis I29 at substantially right angles thereto to expose a maximum surface of the portion I26 to the action of the airflow from the fan 21. To the outside of the plate 36 and mounted on the axis I29 is an insulated contact clockwise direction as viewed in Fig. 7, into engagement with the contact I21, the weight of the sail portion I26 being suflicient to press the contact I21 upwardly into a closed position with v the contact I26. Because of this construction of the sail switch unit I22 the contacts I26 and I21 are in a normally closed position, with the direction of airflow, indicated by the arrow in Fig. 7, tending to pivot the sail portion I25 to w the left,- or in acounter-clockwise direction as also viewed in Fig. 7, which action moves the insulated arm I'3I in an opposite direction to permit opening of the contacts I26 and I2! when the fan 21 is in operation. open position is illustrated in Fi '7.

The'operation of the control system in Fig. 4 is controlled by manipulation of the actuating arm I32 in the control. mechanism H9. The lever arm I32 (Figs. 4, 5 and 6) is mounted at the top of a valve stem I33 for a valve unit indicated generally as I34. The valve stem I33 has a radially extending projection or pin I36 therein for actuating the switch H6 in the engine ignition circuit. When the lever I32 is pointing to an 011" position, indicated in Fig. 4, the pin or projection I 36 is in-its dotted line position shown in Fig. 6, holding the contacts IIB and III in closed position, thus rendering the engine ignition circuit inoperative; This off position of the lever I 32 corresponds also to a closed position of the valve unit I36 inserted in the fuel line I3! connecting the fuel pump 26 with the nozzle ll in the fuel conditioning unit M.

To initiate operation of the heater 22 the lever mechanism H9 in Fig. 4. This movement of the arm I32 from a start to an on"'position opens the valve unit I34 to permit fuel pumped by the pump 26 to be supplied to the fuel conditioning unit 5|. The fuel is thus supplied to the fuel conditioning unit SI only after it is able to be substantially completely vaporized therein, and

only after a prior operation of the air fan 21 and igniter element 2I.

i 32 is moved, from its ofP' to its start position,

as shown in Fig. 4, the relative arrangement of the parts ofthe control mechanism Us for a start position being indicated in full lines in Figs.

4, 5 and 6. This actuation of the lever I32 moves the pin its away from the switch 6 to permit the contacts Iii and Ill toopen, thereby remove ing the ground from the engine ignition circuit and permitting operation of the engine. The valve unit its on movement of the actuating arm 532 from an o to a start position continues to close the fuel line I31 so that no fuel is admitted to the burner on the start position.

The start" position of the lever I32 is defined by the engagement of the pin I36 with the end we of a lever arm I39 (Figs. 5 and 6) pivotally supported intermediate its ends on axis means Mi carried in a portion 182 of the housing H8 for the control mechanism I is. The opposite end of the lever-13B is pivotally connected as at I43 with a stem IM carried on a bellows I09 supported in a casing I48 carried on the heater housing When the heater 22 is to be stopped the lever I32, by virtue of the lever end I being in its downward position as indicated in dotted lines in Fig. 5, is moved directly from an on to an of! position. With the lever I32 in an "01! position the supply of fuel is cut off to the fuel conditioning unit 5i, and the engine ignition circuit is grounded because of the closed position of the contacts II. and III of the'switch H6. The

heater 22 and engine III are thus shut oi! together,

with the heater ignition circuit being rendered inoperative concurrently with the stopping of. the

fan 2'3.

From a consideration of the above description and drawings it is seen that the invention provides a system for controlling a heating unit comsible explosions. The control system 'is of a rugged construction and capable of operating, efliciently and precisely over a long service life with a minimum of servicing. It is further readily adapted for operation when either a magneto or battery is utilized in the operation of the engine.

Although the invention has been described with specific reference to several preferred embodi ments thereof it is to be understood that it is not to be so limited since changes in the partsand I their relative arrangement can be made therein which are within the full intended scope of this invention as defined by the appended claims.

I claim: Y 1. In a control system for a heating unit inv cluding an internal combustion burner opera- Fig. 1. A further description thereof is. thus believed to be unnecessary. With the engine ignition circuit in operation, starting of the engine It provides for the operation of the fan'2'I, the airflow from which in turn operates the sail switch unit I22 to remove the ground from the heater ignition circuit. The heater ignition circuit is thus made operative substantially concurrently with the starting of the engine. As the engine continues to operate the temperatures of the exhaust conduit II and the fuel conditioning unit ii are steadily increased. When the fuel .conditioning unit BI is heated to at least a fuel'vaporizing temperature the bellows I09 01' the sylphon unit I" expands whereby to mov the stem I.

upwardly as viewed in Fig. 5. This direction of -tively connected with an internal combustion engine for concurrent operation therewith and wherein said engine is provided with an exhaust;

a fuel vaporizing device including means define ing a fuel and air mixing chamber from which a mixture of fueLand air may be transmitted to said burner, conduit means for conducting exhaust gases from said engine exhaust through said mixing chamber to provide for the heatin of said chamber and said device by the exhaust gases from said engine-an ignitioncircuit for" said burner including. switch means for operat to retain said valve means in a non-fuel, feed position until said device is heated to a fuel vaporizing temperature by the engine exhaust II of the lever I39 downwardly, as also viewed gases traversing said conduit means. and means responsive to the operation of said engine and acting on said switch means to provide for the operation of said ignition circuit after said engine is started, with said ignition circuit bein in operation prior to the admission of any fuel to said vaporizing device through said valve,

means.

2. In a control system for a heating unit including an internal combustion engine operatively connected with an internal-combustion burner, the combination of an ignition circuit for said burner including switch means adapted to retain said circuit operative only when said engine is in operation, an ignition circuit for said engine including manually operated control switch means, means supplying air for combustion to said burner operatively connected with said engine, a fuel supply system for said burner including valve means for controlling the admission of fuel to said burner, means for actuating said valve means only after said engine has been started so that said ignition circuit and air supply means are in operation prior to the admission of any fuel to said bumenand time delay means connected in said engine ignition circuit to retain the same operative after manual operation of said control switch means to a normal engine shut down osition to provide for a delayed operation of said air supply means.

3. In a control system for heating apparatus including an internal combustion burner operated in conjunction with an internal combustion engine, with said burner having a-fuel vaporizing device adapted to be heated by the exhaust device is at substantially a fuel vaporizing temperature and for preventing said valve means from being operated to an open position until after said burner ignition circuit is in operation.

4. In a control system for heating apparatus including an internal combustion burner operated in conjunction with an internal combustion engine, with said burner having a fuel vaporizing device adapted to be heated by the exhaust gases from said engine, the combination of an ignition circuit for said engine, an ignition circuit for said burner, a fuel system for said burnerwincluding a fuel line operatively associated with said fuel vaporizing device having normal ly closed valve means therein, thermal means responsive in operation to the heat of said vaporizing device for maintaining said valve means closed until said vaporizing device is at substantially a fuel vaporizing temperature, first switch means connected in said engine ignition circuit operation of said engine to provide for the operation of said burner ignition circuit prior to the opening of said valve means to admit fuel to said vaporizing device.

5. In a control system for heating apparatus having an internal combustion burner with a fuel vaporizing device adapted to be heated by the exhaust gases from an internal combustion engine operatively connected with air and fuel supply means for said burner, the combination of an ignition circuit for said burner including switch means adapted to operate said burner ignition circuit concurrently with the operation of said engine and to render the circuit inoperative when said engine is inoperative, an ignition circuit for said engine including a manually actuated control switch, valve means operatively connected with said fuel supply means to control the admission of fuel to said vaporizing device, an actuating arm common to said control switch and valve means, with initial movement of said arm in one direction operating said control switch to permit operation of said engine ignition circuit, and means responsive in operation to the heat of said vaporizing device operatively connected with said actuating arm to lock the same against continued movement in said one direction until said vaporizing device is heated to'substantially a fuel vaporizing-temperature,

tively associated with an internal combustion.

burner having fuel vaporizing means in thermal relation with the exhaust gases from said engine, the combination of an ignition circuit for said burner, an ignition circuit for said engine, a fuel system for said burner including thermally controlled valve means responsive to the temarranged to normally render said engine ignition circuitinoperative, and other switch means conperature of said fuel vaporizing means to admit fuel thereto, a combination valve and switch unit for controlling the flow of fuel to said thermal valve means and for operating said engine ignition circuit, with the actuation of said combination unit to admit fuel to said thermal valve means operating said switch means to make said engine ignitioncircuit operative, with said therder the burner ignition circuit inoperative, and

when said engine is in operation to provide for the operation of said burner ignition circuit.

7. In a control system for a heating unit including an internal combustion engine and an internal combustion burner, with said burner having a fuel vaporizing device adapted to be heated by the exhaust gases from said engine and receiving air for combustion from a blower driven by said engine, the combination of an ignition circuit for said burner, thermostatic switch means connected in said ignition circuit responsive in operation to the heat from said exhaust gases to control the operation of said circuit, a fuel system for supplying fuel to said vaporizing device including a supply line having normally closed valve means therein, and heat responsive means for opening said valve means when said vaporizing device is heated to at least a fuel vaporizing temperature, with said thermostatic switch means being actuated prior to said heat responsive means so that said ignition circuit and blower are in operation before fuel is supplied to said burner through said valve means.

8. In a control system for a heating unit having a burner with a combustion chamber, with i said burner being adapted for operation in conjunction with an internal combustion engine, the combination of an ignition circuit for said engine including thermostatic switch means thermally connected with said combustion chamber so as to be responsive in operation to the heat therefrom, said thermostatic switch means being normally arranged to be ineffective in controlling the operation of said ignition circuit, switch means in said engine ignition circuit including a manually operatedactuating arm, a system for supplying fuel to said combustion chamber including 'a pump operated b said engine and normally closed valve means operatively connected with said actuating arm, and means for supplying air to said combustion chamber operatively connected with said engine, with movement of said actuating arm in one direction opening said valve means and operating said manual switch means to render the engine ignition circuit operative to start said engine, with actuating arm in a reversed direction closing saidvalve means and shutting ofi the fuel supply to said burner to stop the same, said engine continuing in operation until said thermostatic switch means is permitted to return to its normal position by the cooling of said combustion chamber.

9. In a control system for a heating unit having an internal -combustion burner with means for supplying air and fuel thereto operated by a common motor means, the combination of an operating circuit for said motor means including manually operated switch means, valve means operatively associated with said fuel supply means to control the admission of fuel to said burner, an ignition circuit for said burner including said switch means arranged to normally retain said burner ignition circuit inoperative, an actuating lever common to said manual switch means and valve means movable to one operating position for actuating said switch means to operate said motor circuit, said valve means remaining closed at said one lever'operating position, with the air flow from said air supply means on operation of said motor means acting on said sail switch means to make said burner ignition circuit operative, said lever being movable to a second operating position to open said valve means while maintaining said switch means in a nected with said fuel supply means to control the admission of fuel to said vaporizing device,

an actuating arm common to said manual switch means and valve means, with initial movement of said arm in one direction operating said manual switch means to provide for the operation of said engine ignition circuit, said engine on being started operating said air supply means, with the air from said air supply means acting on said sail switch means to render said burner ignition circuit operative, and means responsive in motor operating position, and means for pre-' venting said lever from being operated to said second operating position until after said burner ignition circuit is in operation;

10. In a control system for a heating unit having an internal combustion burner with a fuelvaporizing device adapted to be heated by the exhaust gases from an internal combustion engine operatively connected with the air and fuel supply means for said burner, the combination of an ignition circuit for said burner including sail switch means normally arranged to retain said burner ignition circuit inoperative, an ignition circuit for said engine including manually actuated switch means, valve means operatively conoperation to the heat of said vaporizing device operatively connected with said actuating arm to lock it against continued movement in said one direction until said vaporizing device is heated to at least a fuel vaporizing temperature, with the continued movement of said arm in said one direction opening said valve means to admit fuel to said-vaporizing device.

11. In a control system for a heating unit having an internal combustion burner with means for supplying air and fuel th ereto operated by an internal combustion engine having a source of waste heat, the combination of an operating cirating position actuating said manual switch means .operating position, with the air flow from said air supply means, an operation of said engine, acting on said sail switch means to make said burner ignition circuit operative, and means re sponsive in operation to the heat from said waste heat source operatively connected with said locking means to release said lever for opening said valve meansafter said burner ignition and engine circuits are in operation.

12. In a control system for a heating unit which includes a heater provided with a combustion chamber, a fuel vaporizing unit for delivering fuel to said chamber, an internal combustion engine and means for utilizing the exhaust gases from said engine to heat parts of said unit to a fuel vaporizing temperature; the combination which includes an ignition circuit for said heater, means supplying fuel to said unit, means for preventing fuel from being delivered to said unit before said parts of'saidheater are heated to a fuel vaporizing temperature by the exhaust gases from said engine, and means controlled by the heated exhaust gases from said engine for controlling the energization of said ignition circuit.

13. In a control system for heating apparatus operative to supply combustion air to said heater,

a fuel supply system for said heater, means for controlling said fuel supply system to arrest the operation of said heater, and means controlled in accordance with the heat generated by said heater for arresting the operation of said engine a short time interval following the operation of said last-named means.

15. In a control system for heating apparatus which includes a heater provided with a combustion chamber, a fuel vaporizing unit for deliver- I ing a mixture of fuel and air to said combustion chamber, an internal combustion engine and means'for utilizing waste heat from said engine to heat the parts of said unitto a fuel vaporizing temperature; the combination which includes a fuel ignition circuit for said heater, and thermal responsive means controlled by the heat generated by said engine for selectively closing said circuit.

16. In a control system for heating apparatus which includes a heater provided with a combustion chamber, a. fuel vaporizing unit for delivering a mixture of fuel and air to said combustionchamher, an internal combustion engine and means for utilizing waste heat from said engine to heat the parts of said unit to a fuel vaporizing. temperature; the combination which includes normally inactive means for supplying fuel to said unit, and means responsive to the heating of said parts of said unit to a fuel vaporizing temperature by the waste heat from said engine for conditioning said fuel supply means to supply fuel to said unit.

17. In a control system for heating apparatus which includes an internal combustion engine capable of producing waste heat, a heating unit including means defining a combustionchamber, a normally inoperative ignition circuit including means for igniting fuel within said chamber, switching means operative to render said circuit operative in response to operation of said engine, means driven by said engine for supplying combustion air to said chamber, a fuel supply system for said chamber including valve means for controlling the admission of fuel to said chamber, thermal responsive means operative in response to the waste heat developed by said engine during its operation, and means connecting said thermal r'esponsivemeans and said valve means to retain said valve means closed until after said engine is in operation, thereby to insure operation of said air supply means and energization of said ignition circuit prior to the admission of fuel to said chamber through said valve means.

18. In heating apparatus which includes an internal combustion engine provided with an exhaust, a heating unit including means defining a combustion chamber having an inlet, a fuel and air mixing and vaporizing device provided at said inlet and including means defining a mixing chamber communicating with said combustion chamber, means driven by said engine for supplying air to said mixing chamber, a fuel supply system including means'driven by said engine for supplying fuel to said mixing chamber, valve means included in said, fuel supply system for controlling the admission of fuel to said mixing chamber, conduit means-for conducting exhaust gases from said engine exhaust through said mixing chamber and for discharging the gases into said combustion chamber, an ignition circuit including means for igniting fuel within said combustion chamber, switching means operative to render said circuit operative in response to operation of said engine, thermal responsive means operative in response to the heat of said exhaust gases and including heat absorbing means arranged in heat exchange relationship with said conduit means within said mixing chamber, and means connecting said thermal responsive means and said valve means to retain said valve means closed until after said engine is in operation, therein to insure operation of said air supply means and energization of said circuit prior to the admission of fuel to said mixing chamber through said valve means.

19. In heating apparatus which includes an internal combustion engi e provided with an exhaust, a heating unit including means defining a combustion chamberhaving an inlet, a fuel and air mixing and vaporizing device provided at'said inlet and including means defining a mixing chamber communicating with said combustion chamber, a fuel supply system including valve means for controlling the admission of fuel to said mixing chamber, conduit means for conductingv exhaust gases from said engine exhaust through said mixing chamber and for discharging the gases into said combustion chamber, an ignition circuit including means for igniting fuel within said'combustion chamber, switching means operative to render said circuit operative in response to operation of said engine, thermal responsive means operative in response to the heat of said exhaust gases and including heat absorbing means arranged in heat exchange relationshi with said conduit means within said mixing chamber, and means connecting said thermal responsive means and said valve means to retain said valve means closed until after said engine is in operation, thereby to insure operation of said air supply means and energization of said circuit prior to the admission of fuel to said mixing chamber through said valve means.

HARRY B. HOLTHOUSE. 

